The invention relates to an elastic shaft coupling comprising at least one torsion element that, as a transfer element, comprises an elastomer body, on which connection flanges are secured.
One problem afflicting shaft couplings of the type specified above known from the prior art is the fact that the elastomer body contracts axially especially at higher numbers of revolution. This has to be ascribed to the fact that the relatively soft elastomer attempts to yield outwards under the influence of the centrifugal forces, causing the connecting flanges to be pulled together. This effect is compounded even further under the torsional shearing stress occurring in the transmission of the torque. This effect is particularly pronounced if the elastomer body is made of a particularly soft material, or penetrated by cooling apertures. The axial movements of the connection flanges have to be compensated in the adjoining assemblies, which means that substantial expenditure is required.
It is known according to the prior art (e.g. from DE-C-37 10 390 and DE-A-4 34 722) to interrupt the elastomer body of an elastic shaft coupling in the center by providing it with ring-shaped disks, which are attached to the coupling by vulcanization and supported on the shaft on the inside. These ring disks and their support, however, mean that substantial additional expenditure is required, and that the resilience of the elastic shaft coupling is adversely affected.
It is already known from U.S. Pat. No. 3,910,068 to support the elastomer body of an elastic shaft coupling by means of a cylindrical tube against buckling directed outwards in the radial direction. The proposed design, however, has a number of drawbacks. The supporting cylindrical tube obstructs the torsional motion and, within the framework of shearing conditioned by torsion, leads to relative movements between the elastomer body and the rigid cylindrical tube that cause wear. Furthermore, the support by means of the cylindrical tube obstructs the dissipation of heat from the elastomer body and results in destruction of the elastomer body by heat when higher outputs need to be transmitted.
Therefore, the problem of the invention is to further develop the elastic shaft coupling of the type specified above to the extent that the axial shortening of the elastomer body is reduced while its resilience is impaired to the least possible extent.